The spider family

Spiders belong to the group of animals called arthropods. All arthropods have jointed legs and include crustaceans (crabs belong to this group) insects, which have six legs and arachnids, which have eight legs. Spiders have eight legs and belong to the arachnid group which also includes scorpions and ticks.

Spiders in Australia

There are more than 30,000 different kinds of spider and 2,000 of them live in Australia. Only a few of the Australian ones are dangerous: these include the red-back spider, the Sydney funnel-web spider and white-tailed spiders.

Other spiders such as the wolf spiders and the large bird-eating spider look fierce but are not usually a danger to people. Some people keep bird-eating spiders as pets!

Habitat and distribution (where they are found)

Spiders live almost everywhere, even in the Arctic and on mountain tops. They live where they can find food. They live on plants, near swamps, underground, in caves and in deserts. One kind of spider spends most of its life under water. Some spiders live in our houses, in sheds or other buildings. Others live on the outside walls of buildings or in the corners of windows.

A Spider's Body

A spider's body is divided into two main parts, the head and the abdomen. All spiders have eight legs, which are attached to the abdomen. Spiders have claws on the end of their hairy legs which help them walk on a web and sense movement nearby. They have mouth parts called pedipalps. To eat their prey, they suck the juices out of it because they cannot chew it.

Most spiders have eight eyes.

Spiders Catching food

All spiders spin silk. Some make webs with the silk to catch insects for food. The webs are spun by the spiders using sticky silk from inside their bodies. When the prey flys into the web it gets stuck.

The spider feels the trapped insect moving in the web and quickly grabs it.

Q.Why doesn't the spider get caught in its own web?

A. The spider has a hooked claw on each leg which it uses to hold the silk.

Some kinds of spiders do not make webs. They catch food by jumping on it. Some spiders hide and wait for prey to come close.

All spiders have hollow fangs and most use them to inject poison into their prey when they capture it.

Spiders eat insects but some spiders eat tadpoles, small frogs and fish, and mice. Spiders sometimes eat each other. Female redback spiders often eat the smaller, male redback spiders.

Life cycle of spiders

After mating with a male spider the female lays eggs. The spider wraps her eggs inside a sac made of silk. Some spiders hide the egg sac while others carry it with them. When the eggs hatch, the baby spiders, called spiderlings, shed their skins as they grow.

Sydney Funnel-Web spider

Sydney Funnel-web spiders are large black spiders and can be up to 7 millimetres long.

The male is smaller than the female. The body is covered with fine hairs and they have shiny legs.

They live in small, neat holes lined with a collar of silk in moist, shady places under rocks, shrubs, logs and leaf litter. Silk threads lead away from the entrance to the burrow, and act as trip lines. When prey walks into them, the spider dashes out to grab it.

Funnel-webs eat beetles, cockroaches, snails and sometimes small frogs and lizards.

Females mate with a male and then lay 80 - 250 eggs, which she wraps in a silk egg sac. She keeps the sac inside her burrow and guards it until the spiderlings (young spiders) hatch. The young share their mother's burrow for a few weeks before wandering off to find a place of their own to live.

Male Sydney funnel-webs die a few months after mating. Females can live and breed for a few years.

A dangerous spider

The male Sydney funnel-web spider is a dangerous spider. It is aggressive and will not run away. A bite from this spider is very painful. A bitten person must be treated quickly.

There is an antivenom (medicine that lessens the effect of the spider's poison) which prevents people from becoming very ill, or even dying from a bite from a Sydney funnel-web spider.

[*Click to find an inquiry learning/research skills practice sheet about funnel-webs]

Redback spiders

Redback spiders belong to a group of spiders known as widow spiders.

Female redback spiders have shiny black bodies with red markings on the top of the abdomen. Their bodies are about the size of a large pea. Male redback spiders are smaller than the females and their colours are paler.

Redbacks live in all parts of Australia, in sheds, garages, and under steps, logs and rocks.

Females build sticky, tangled webs in dry, sheltered places and hide inside the funnel- shaped space at the top of the web. Male redbacks do not make webs but live near the female's web.

When prey is caught in the web, the spider ties it up into a bundle and carries it into the web to bite and kill it. Then she sucks out the juices from the body of the prey.

The female redback, after mating with the male, produces up to ten white, round egg sacs. Each sac can contain up to 250 eggs. After they hatch the spiderlings float away on silk threads to find somewhere to live. Females may live for two or three years. Males live only for six months. Many males are eaten by the females after mating!

A bite from a female redback spider is painful and dangerous!

The poison is highly venomous. There is an antivenom that will lessen the effects of the spider's poison. Male redback spiders bite but their fangs are too small to pierce human skin.

White-tailed spiders

White-tailed spiders have cylinder shaped bodies about 1 to 2.5 centimetres long.

They are dull dark-grey or brown in colour, with a creamy white or grey spot on the end of their abdomen.

White-tailed spiders live in most parts of Australia in and around houses. They don't make webs, but hide under bark, rocks and leaf litter. They wander about at night in search of prey, especially black house spiders. White-tailed spiders will catch and eat redback spiders.

They often hide in bed linen, in clothes left on the floor, and in wardrobes and behind curtains.

After mating with a male white-tailed spider, the female lays up to 100 eggs in a silken sac.

A bite from this spider is painful and the bitten person will feel unwell.

The area of the bite should be washed with soapy water to stop infection. There is no antivenom for the poison of the white-tailed spider!

It is always a good idea to use more than one source of information, so here are some others for you to investigate

Read about spider bodies:

https://study.com/academy/lesson/spider-anatomy-lesson-for-kids.html

Facts about spiders

Watch a video about spiders